Slot antenna with orthogonally positioned slot segments for receiving electromagnetic waves having different polarizations

ABSTRACT

An antenna for receiving electromagnetic waves having different polarizations that comprises a plurality of slots defined by a piece of metal, and each of the plurality of slots includes at least two continuous segments. In addition, for each of the plurality of slots: a first segment of the at least two continuous segments is: (i) defined by the piece of metal in a first dimension, and (ii) configured to receive radio frequency (RF) power transmission waves having a first polarization, and a second segment of the at least two continuous segments is: (i) defined by the piece of metal in a second dimension, distinct from the first dimension, and (ii) configured to receive RF power transmission waves having a second polarization different from the first polarization.

This application is a continuation of U.S. patent application Ser. No. 14/930,531, filed on Nov. 2, 2015, entitled “3D Triple Linear Antenna That Acts As Heat Sink,” which is herein fully incorporated by reference in its respective entirety.

TECHNICAL FIELD Background

Wireless charging of batteries of electronic devices has historically been performed by using inductive coupling. A charging base station receiver of an electronic device may have one or more coils in which a current may be applied to produce a magnetic field such that when another coil is place in close proximity, a transformer effect is created and power is transferred between the coils. However, such inductive coupling has a short range limit, such as a few inches or less. Examples of such wireless charging include electronic toothbrushes that are placed on a charging stand and inductive pads inclusive of one or more coils to enable electronic devices with coil(s) to be placed on the pads to be charged.

While inductive charging is helpful to eliminate users having to plug power cords into electronic devices for charging, the limited range at which electronic devices have to be positioned from charging stations is a significant shortcoming of the inductive charging technology. For example, if a user of a mobile device, such as a mobile telephone, is in a conference room without a charging pad or sufficient number of charging pads, then the user is unable to charge his or her phone without a traditional power cord.

Remote wireless charging has recently been developed. Remote wireless charging operates by generating a wireless signal inclusive of sufficient power to charge a battery of an electronic device. Such technology, however, has been limited due to technology advancements being a challenge, as transmitters, receivers, antennas, communications protocols, and intelligence of transmitters have all had to be developed (i) so that sufficient wireless power is able to be wirelessly directed to charge electronic devices and (ii) so that the remote wireless charging is effective and safe for people.

Electronic devices are becoming smaller and as such, receivers and antennas for receiving wireless power to charge the electronic devices are also to become smaller. Such receivers and antennas are to be able to receive multi-polarized wireless power signals in order to be more efficient in receiving and charging wireless power signals.

SUMMARY

An antenna adapted to be used by a remote wireless charging receiver at an electronic device may include a printed circuit board on which an application specific integrated circuit (ASIC) may be attached to and/or supported by a stamped 3D slot dipole antenna that also operates as a heat sink. The use of the stamped slot dipole antenna actually provides for multiple antenna elements, such as four, that may receive signals in three orthogonal planes. As a result, the receiver may operate in an efficient manner when receiving a wireless power signal that is dual-polarized or circularly polarized, and allows the receiving antenna to be in any orientation relative to the transmitter antenna without losing efficiency.

One embodiment of a receiver for receiving wireless waves to power a device may include an electronic circuit configured to receive wireless radio frequency waves and convert the radio frequency waves into a signal that can be used to power the device. An antenna device may be configured to at least partially house the electronic circuit and to operate as a heat sink for the electronic circuit. The antenna may further be configured to receive the radio frequency waves in a plurality of polarizations (e.g., x, y, and z-axes). In housing the electronic circuit, the antenna may cover the electronic circuit positioned on a PCB. There may be three polarizations.

One embodiment of a method of manufacturing a receiver antenna and heat shield may include providing a piece of metal. The piece of metal may be stamped to form a 3D slot dipole antenna. The 3D slot dipole antenna may be secured to a printed circuit board inclusive of an electronic circuit to form a receiver configured to receive and convert wireless power.

One embodiment of an antenna may include a piece of metal defining multiple antenna sections inclusive of 3D slot dipoles. The 3D slot dipoles may be configured to receive RF signals in multiple polarizations.

Additional features and advantages of an embodiment will be set forth in the description which follows, and in part will be apparent from the description. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the exemplary embodiments in the written description and claims hereof as well as the appended drawings.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings constitute a part of this specification and illustrate an embodiment of the invention and together with the specification, explain the invention.

FIG. 1 is an illustration of an illustrative wireless power environment in which transmitters may be configured to identify locations of one or more receivers inclusive of stamped 3D slot dipole antennas, and to communicate wireless power signals to those receiver(s) to form energy pocket(s) thereat, according to an exemplary embodiment;

FIG. 2 is an illustration of an illustrative PCB for mounting an ASIC configured to convert RF signals communicated as remote wireless power signals, according to an exemplary embodiment;

FIG. 3 is an illustration of an illustrative stamped 3D slot dipole antenna, according to an exemplary embodiment;

FIG. 4 is an illustration of an alternative illustrative stamped 3D slot dipole antenna, according to an exemplary embodiment;

FIG. 5 is an illustration of the stamped 3D slot dipole antenna of FIG. 3 mounted to the PCB of FIG. 2, according to an exemplary embodiment;

FIGS. 6A and 6B are illustrations of respective top and bottom isometric views of an alternative illustrative stamped 3D slot dipole antenna, according to an exemplary embodiment; and

FIG. 7 is a flow diagram of an illustrative process for manufacturing a receiver inclusive of a 3D slot dipole antenna to receive wireless power signals to charge a battery of an electronic device.

DETAILED DESCRIPTION

The present disclosure is herein described in detail with reference to embodiments illustrated in the drawings, which form a part here. Other embodiments may be used and/or other changes may be made without departing from the spirit or scope of the present disclosure. The illustrative embodiments described in the detailed description are not meant to be limiting of the subject matter presented here. Alterations and further modifications of the inventive features illustrated herein, and additional applications of the principles of the inventions as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention.

Referring to FIG. 1, an illustration of an illustrative wireless power environment 100 in which transmitters 102 a, 102 b (collectively 102) are configured to identify a location of an electronic device 104 with a receiver 106 (or multiple receivers) inclusive of one or more receiver antennas (e.g., cross-polarized dipole antenna), and transmit wireless power signals or waves to the receiver 106 to cause RF signal constructive interference to form at the receiver 106 is shown. Although depicted with multiple transmitters 102, it should be understood that a single transmitter may be utilized. The transmitters 102 a, 102 b respectively include antenna arrays 108 a, 108 b (collectively 108) inclusive of respective antenna elements 109 a-109 m, 109 n-109 z (collectively 109). The transmitters 102 are used to transmit wireless power signals 110 a, 110 a (collectively 110) via the antenna elements 109. In one embodiment, the antenna arrays 108 a, 108 b have the same number of antenna elements. Alternatively, the antenna arrays 108 a, 108 b have a different number of antenna elements. Still yet, the antenna arrays 108 a, 108 b may have the same or different layouts or configurations of antenna elements. The antenna arrays 108 a, 108 b may have regularly spaced antenna elements or subsets of antenna elements with different spacings that are used for different types of transmissions of the wireless power signal.

Because the transmitters 102 are meant to be positioned in households and commercial settings, such as conference rooms, the transmitters 102 are to be sized in a manner with a small footprint and/or profile. Although the size of the footprint (e.g., width of overall antenna arrays) in some cases has to have a certain length for creating small energy pockets, the profiles (e.g., length of the antenna elements 109 along the z-axis that define the distance that the transmitters 102 extend from a wall) can be reduced to be more commercially viable for adoption by consumers and businesses.

The transmitters 102 may also include communication components 112 a, 112 b (collectively 112) that communicate with the electronic device 104. In one embodiment, the receiver 106 may be configured with a transmitter or other circuitry that enables communication with the communication components 112, thereby enabling the transmitters 102 to focus the wireless power signals 110 at the receiver 106 to form an energy pocket 114. The energy pocket 114 may be a localized region at which wireless power waves 110 form constructive interference (i.e., peaks of oscillation signals coincide and add constructively) that produces a combination of peak signals from each of the wireless power signals 110.

Because the antenna arrays 108 may have orientations that cause the wireless power signals 110 to be communicated at different polarizations depending on an orientation of the electronic device with respect to the respective antenna arrays 108, the receiver 106 may include a cross-polarized dipole antenna, for example, so that orientation of the receiver 106 with respect to the antenna arrays 108 has minimal impact in an amount of power that is received from the wireless power signals 110.

To provide for cost effective antenna arrays 108, a structure for each of the antenna elements 109 may utilize a design that has a minimal number of parts and simplistic assembly process. The antenna element may be configured to transmit a wireless power signal having a frequency over 900 MHz to be transmitted to charge or operate a wireless device. In an embodiment, the antenna arrays 108 are configured to transmit at frequencies over 1 GHz. However, the antenna arrays 108 can be configured to operate at frequencies in a range from over 1 GHz to 100 GHz. More specifically, the center frequency may be about 1 GHz, 5.8 GHz, 24 GHz, 60 GHz, and 72 GHz with bandwidths suitable for operation (e.g., 200 MHz-5 GHz bandwidths), and the dimensions may be configured to accommodate the frequencies of operation. The wireless power signal may be an RF signal that is circularly polarized or dual-polarized depending on the configuration of the antenna, as understood in the art.

With regard to FIG. 2, an illustration of an illustrative PCB 200 for mounting an electronic device, such as an ASIC, configured to convert RF signals communicated as remote wireless power signals is shown. The PCB 200 includes a dielectric material 202 disposed on a substrate 204, as understood in the art. Conductive lines 206 a-206 d (collectively 206) are configured to receive and conduct RF signals from an antenna. A pad 208 on which an electronic circuit, such as an ASIC, may be affixed is centrally located on the PCB 200. It should be understood that the pad 208 may be located elsewhere on the PCB 200. Conductive pads 210 that may extend through thru-hole vias 212 (i.e., conductors through the PCB 200) may be utilized to conduct signals, such as power signals, from the electronic device positioned on the pad 208 to another device, such as a mobile telephone, for charging a rechargeable battery or otherwise operating the electronic device.

With regard to FIG. 3, an illustration of an illustrative stamped 3D slot dipole antenna 300 is shown. The antenna 300 includes four antenna regions 302 a-302 d (collectively 302). Within each of these antenna regions 302, four 3D slot dipoles 304 a-304 d (collectively 304) are positioned. Each of the 3D slot dipoles are shown to include dipole slots 306 x, 306 y, and 306 z that are orthogonal to one another, such that the antenna regions 302 are each configured to receive RF signals that are dual polarized or circularly polarized in any of the axes, thereby being more efficient than if the slots were oriented in only one or two planes. Having the dipole slot 306 z enables receiving RF signals when the antenna 300 is oriented orthogonal to the transmitter antenna if transmitting dual-polarized RF signals.

The antenna 300 also includes a plurality of feet 308 a-308 d (collectively 308) that may be attached to conductive lines 206 of FIG. 2 to support the antenna 300 and to transfer RF signals received by the 3D slot dipoles 304 to an electronic circuit residing on the PCB 200 for converting wireless power signals into wireless power for use in charging or powering an electronic device. The antenna 300 may include chamfers 310 a-310 d (collectively 310) that may be used to enable bending of the antenna regions 302 to form a vertical height H so as to provide for the z-axis dipole slot 306 z for each of the antenna regions 302. The antenna 300 may be a stamped piece of metal, which provides for low-cost manufacturing, as understood in the art. By using a single, stamped piece of metal for producing the antenna 300, manufacturing and assembly complexity may also be minimized.

With regard to FIG. 4, an illustration of an alternative illustrative stamped 3D slot dipole antenna 400 is shown. The antenna 400 may have the same or similar features, such as 3D slot dipoles 304 and 402, but the height H of the antenna 400 may be higher than the height H of the antenna 300 of FIG. 3. In both of the antennas 300 and 400, the 3D slot dipoles are configured to be in x, y, and z axes. It should be understood that configurations and dimensions of the 3D slot dipole antennas 300 and 400 may be varied depending on frequencies and frequency bands being received, as understood in the art.

With regard to FIG. 5, an illustration of the stamped 3D slot dipole antenna 300 of FIG. 3 mounted to the PCB 200 of FIG. 2 is shown. As previously described, the feet 308 may be physically and electrically connected to the conductive lines 206 on the PCB 200. In connecting the antenna 300 to the PCB 200, a conductive adhesive (not shown) may be utilized so that an RF signal may be transferred between the antenna 300 and conductive lines 206. The feet 308 may be elongated and sized to match electrical conductive lines 206 on the PCB 200. By elongating the feet 308, the antenna 300 may operate as a heat sink for heat produced by the electronic circuit that travels along the electrical conductive lines 206. As shown, the antenna 300 is configured to at least partially house the electronic device by being affixed to the PCB 200 on which the electronic device (e.g., ASIC) is also affixed. That is, the antenna 300 is positioned on one side of the electronic device and the PCB 200 is positioned on the other side. It should be understood that in placing the antenna over the electronic device, antenna height may be selected to assure physical contact between the antenna and the packaging of the ASIC, thereby enabling more efficient transfer of heat from the electronic device to the antenna, whereby the antenna acts also as a heat sink. It should also be understood that the physical contact between the electronic device, such as an ASIC, and the antenna may include a heat conductive adhesive or lubricant to make conducting of heat from the electronic device to the antenna more effective.

With regard to FIGS. 6A and 6B, illustrations of respective top and bottom isometric views of an alternative illustrative stamped 3D slot dipole antenna 600 are shown. The antenna 600 includes four antenna sections 602 a-602 d (collectively 602) inclusive of respective 3D slot dipoles 604 a-604 d (collectively 604). As with the antenna 300 of FIG. 3, the antenna 3D slot dipoles 604 provide for receiving RF signals in three polarizations (i.e., x, y, and z-axis polarizations). As shown in FIG. 6B, the bottom of the antenna 600 defines an opening 606 in which a cavity 608 may have an electronic device, such as an ASIC (not shown) that includes rectifiers, in this case four rectifiers or one for each of the antenna sections 602, to convert the received wireless power signals received by the respective antenna sections 602. As configured, the antenna 600 may operate as a (i) carrier for housing an electronic device and (ii) heat sink for dissipating heat produced by the electronic device in converting the wireless power signals into alternative power signals (e.g., DC power signals) for use in charging or providing operating power for an electronic device (e.g., mobile telephone). Four feeding points 610 a-610 d used to transition the received RF signals onto the PCB are located at the inner portion of the respective 3D slot dipoles 604.

With regard to FIG. 7, a flow diagram of an illustrative process 700 for manufacturing a receiver inclusive of a 3D slot dipole antenna to receive wireless power signals to charge a battery of or operate an electronic device is shown. The process 700 may start at step 702, where a piece of metal may be provided. At step 704, the piece of metal may be stamped to form a 3D slot dipole antenna. The 3D slot dipole antenna may include multiple 3D slot dipoles. In one embodiment, four 3D slot dipoles may be stamped into the metal. The stamping of the metal may also form feet at the bottom of the edges of the 3D slot dipole antenna, where the feet may be configured to secure the 3D slot dipole antenna to electrical conductor lines of a PCB. The 3D slot dipole antenna may be configured to provide for receiving dual or circularly polarized RF signals in multiple polarizations or orientations, such as along the x, y, and z axes. At step 706, the 3D slot dipole antenna may be secured to a PCB inclusive of an electronic circuit configured to convert wireless power. The securing of the antenna to the PCB may include securing respective antenna sections to respective conductive lines that are electrically connected to the electronic circuit to enable received RF signals to be converted into power signals for charging or operating an electronic device inclusive of the antenna. The electronic circuit may be an electronic circuit inclusive of multiple rectifiers, such as one rectifier for each 3D slot dipole.

The foregoing method descriptions and the process flow diagrams are provided merely as illustrative examples and are not intended to require or imply that the steps of the various embodiments must be performed in the order presented. The steps in the foregoing embodiments may be performed in any order. Words such as “then,” “next,” etc. are not intended to limit the order of the steps; these words are simply used to guide the reader through the description of the methods. Although process flow diagrams may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination may correspond to a return of the function to the calling function or the main function.

The preceding description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the following claims and the principles and novel features disclosed herein. 

1. An antenna for receiving electromagnetic waves having different polarizations, comprising: a plurality of slots defined by a piece of metal, wherein each of the plurality of slots comprises at least two continuous segments, wherein, for each of the plurality of slots: a first segment of the at least two continuous segments is: (i) defined by the piece of metal in a first dimension, and (ii) configured to receive radio frequency (RF) power transmission waves having a first polarization; and a second segment of the at least two continuous segments is: (i) defined by the piece of metal in a second dimension, distinct from the first dimension, and (ii) configured to receive RF power transmission waves having a second polarization different from the first polarization.
 2. The antenna of claim 1, wherein: the antenna is connected to an electronic circuit; and the electronic circuit is configured to convert the RF power transmission waves received by the antenna into usable power for powering an electronic device or charging a battery of the electronic device.
 3. The antenna of claim 2, wherein: the piece of metal is configured to: (i) at least partially house the electronic circuit, and (ii) operate as a heat sink for the electronic circuit.
 4. The antenna of claim 2, wherein: the electronic circuit is mounted on a circuit board having a plurality of conductive traces; the electronic circuit is coupled with respective first ends of the plurality of conductive traces; and feet of the piece of metal are coupled with respective second ends of the plurality of conductive traces, thereby coupling the antenna with the electronic circuit.
 5. The antenna of claim 4, wherein: the respective second ends of the plurality of conductive traces are formed along a perimeter of the circuit board; and the feet of the piece of metal substantially cover the perimeter.
 6. The antenna of claim 1, wherein the at least two continuous segments included in each of the plurality of slots are substantially orthogonally positioned relative to each other.
 7. The antenna of claim 1, wherein the first dimension is orthogonal to the second dimension.
 8. The antenna of claim 1, wherein: a first slot of the plurality of slots is oriented along a first axis; a second slot of the plurality of slots is oriented along a second axis; and the first axis is substantially orthogonal to the second axis.
 9. The antenna of claim 8, wherein: the first slot has a shape; the second slot also has the shape; and the first and second slots are distinct and separate from each other.
 10. The antenna of claim 9, wherein: a third slot of the plurality of slots is oriented along the first axis; the third slot also has the shape; the first slot is oriented in a first direction along the first axis; the third slot is oriented in a second direction along the first axis, the second direction being opposite to the first direction; and the third slot is distinct and separate from the first and second slots.
 11. The antenna of claim 1, wherein: a first segment of the at least two continuous segments in each of the plurality of slots is defined by a surface of the piece of metal; feet of the piece of metal are offset from the surface of the piece of metal; sidewalls of the piece of metal extend from the feet to the surface; and a second segment of the at least two continuous segments in each of the plurality of slots is defined by one of the sidewalls of the piece of metal.
 12. The antenna of claim 11, wherein: the surface of the piece of metal is in the first dimension; and the sidewalls of the piece of metal are in the second dimension.
 13. The antenna of claim 11, wherein the antenna operates as a heat sink by dissipating heat via the feet of the piece of metal.
 14. The antenna of claim 11, wherein the second segment of the at least two continuous segments in each of the plurality of slots is further defined by the feet of the piece of metal.
 15. The antenna of claim 1, wherein the RF power transmission waves are transmitted by a remote transmitter.
 16. The antenna of claim 1, wherein the piece of metal operates as a heat sink for the electronic circuit while the RF power transmission waves are being received by the antenna.
 17. The antenna of claim 1, wherein: the RF power transmission waves having the first polarization are horizontally polarized RF power transmission waves; and the RF power transmission waves having the second polarization are vertically polarized RF power transmission waves.
 18. The antenna of claim 1, wherein each of the plurality of slots further includes a third segment that is: (i) defined by the piece of metal in a third dimension, distinct from the first and second dimensions, and (ii) configured to receive RF power transmission waves having a third polarization.
 19. The antenna of claim 18, wherein, for each of the plurality of slots: the first segment is defined substantially along the x-axis; the second segment is defined substantially along the y-axis; and the third segment is defined substantially along the z-axis.
 20. A method of manufacturing an antenna, the method comprising: stamping a piece of metal, wherein: the stamped piece of metal defines a plurality of slots; and each of the plurality of slots comprises at least two continuous segments, where: a first segment of the at least two continuous segments is: (i) defined by the piece of metal in a first dimension, and (ii) configured to receive radio frequency (RF) power transmission waves having a first polarization; and a second segment of the at least two continuous segments is: (i) defined by the piece of metal in a second dimension, distinct from the first dimension, and (ii) configured to receive RF power transmission waves having a second polarization different from the first polarization. 